The present invention relates to devices for analyzing electrical induction machines, and more particularly, to devices for analyzing electric induction motors by performing high-voltage and low-voltage tests on the motors.
With increasing deregulation of electric utilities, many electric utility companies find themselves in competition with other electric utilities. In order to successfully compete, many electric utilities have focused their efforts on reducing operation and maintenance costs associated with generation of electrical power. A significant aspect of such cost reduction is concentrated on predictive maintenance, or condition-based maintenance programs, designed to provide "just-in-time" maintenance to operational equipment.
In electrical utility stations, an important class of operational equipment which can significantly benefit from predictive maintenance includes the many induction machines, such as electric motors, in operation. Electric motors are expensive machines and are crucial to providing uninterrupted power to consumers. An important battery of tests for implementing predictive maintenance on electric motors includes high-voltage testing and low-voltage testing of the electric motors. These tests include measuring insulation resistance, conductor resistance, and impedance. Both high-voltage tests and low-voltage tests are necessary to determine the status of electric motors and to perform preventative maintenance.
In performing such tests, electric utilities currently utilize a number of devices, including at least one device for high-voltage testing and at least one device for low-voltage testing of electric motors. As such, an operator must physically carry several test devices to each electric motor in order to perform a complete set of tests on the motors. The operator must then electrically connect each device to an electric motor, perform a desired test, disconnect the device from the electric motor, and repeat the entire procedure for the next motor. This is highly disadvantageous because the operator must carry around several devices, and individually connect and disconnect the test devices from an electric motor being tested.
Further, existing testing devices do not provide built-in "intelligence" to automatically process the test results and make determinations as to the status of a tested motor. Currently, an operator who performs the tests has to also review the results of the tests to determine whether a motor requires maintenance, repairs or otherwise. However, most individuals assigned to testing do not have the required training to make informed decisions about the status of the electric motor based on the test results. Therefore, the test results must be communicated to a specialist who can determine the status of the electric motors and suggest a course of action. This is unsatisfactory, however, because of the excessive person power involved in performing tests and in analyzing the tests results, and because of the delay inherent in having the test results reviewed by a specialist.
There is, therefore, a need for an induction machine analyzer to allow performing both high voltage and low voltage testing of an induction machine using the same analyzer. There is also a need for the analyzer to have built-in intelligence to process the test results and provide information about the status of the induction machine tested.